Viva Questions for Biology

Biology vivas place significant emphasis on experimental design, data interpretation, and the broader significance of your findings within the life sciences. Examiners will expect you to defend your choice of model organism or system, explain your experimental controls, and demonstrate that you understand the limitations of your techniques. Whether your research is molecular, ecological, or computational, you'll need to show that your conclusions are well supported by your data.

The breadth of biology as a discipline means that viva experiences vary widely. A molecular biologist will face very different questioning from an ecologist or a bioinformatician. However, the common thread is an expectation that you understand your experimental system deeply – not just the protocols you followed, but the principles behind them and what could go wrong.

Questions about your research

Biology examiners are often practising researchers themselves, and they'll ask questions that reflect the kinds of challenges they face in their own work. They want to know that you can think like a scientist – that you understand why controls matter, why reproducibility is essential, and why negative results can be just as informative as positive ones. Expect them to probe the details of your experimental design and to challenge you on decisions that might seem routine.

• Why did you choose this particular model organism or system, and what are its advantages and limitations for your research question?
• Can you walk us through the design of your key experiments, including the controls?
• How did you ensure the reproducibility of your results across biological and technical replicates?
• Were there any unexpected findings, and how did you follow them up?
• What statistical methods did you use to analyse your data, and why were they appropriate?
• How did you address potential confounding variables in your experimental design?
• If you had unlimited resources and time, how would you extend these experiments?
• Can you describe any experiments that failed, and what you learned from them?
• How did you determine your sample sizes, and were they sufficient for the conclusions you've drawn?
• What quality control steps did you apply to your data before analysis?
• How did you handle variability between biological replicates?

Questions about theory and literature

In biology, examiners will want to see that you understand the broader scientific context of your work – not just the immediate papers you've cited, but the trajectory of research in your area. They may ask you to explain competing hypotheses, to evaluate the strength of evidence for different models, or to reflect on how your work fits into a larger puzzle. Being able to articulate where your research sits in the field is a sign of intellectual maturity.

• How does your work contribute to the current understanding of this biological process or system?
• Where does your research sit within the broader field – is it filling a gap, testing a hypothesis, or challenging an existing model?
• Which key papers have shaped your thinking, and how does your work build on them?
• Are there competing hypotheses in your field, and how does your data distinguish between them?
• How has the scientific understanding of your topic evolved during the course of your PhD?
• What assumptions underpin your experimental approach, and how robust are they?
• How does your work relate to advances in technology or technique that have emerged during your research?

Questions about contribution and impact

Biology examiners will be interested in both the immediate scientific contribution of your work and its broader implications. Depending on your subfield, this could mean translational applications in medicine, implications for conservation or agriculture, or new methodological approaches that other researchers could adopt. Be specific about what your work adds – vague claims about "advancing understanding" won't satisfy a rigorous examiner.

• What is the most significant finding in your thesis, and why does it matter?
• What are the translational or applied implications of your work?
• How might your findings influence future research directions in this area?
• Could your results have implications beyond your immediate field – for medicine, conservation, agriculture, or biotechnology?
• If you were to publish one chapter as a standalone paper, which would it be and why?
• What new techniques or approaches does your work introduce that others could use?

Tough follow-ups your examiners might ask

Biology examiners are skilled at identifying the weak points in experimental work. They'll push on sample sizes, alternative explanations, and the robustness of your conclusions. The key is not to be defensive but to show that you've thought about these limitations honestly. Acknowledging a weakness and explaining how you'd address it in future work is far more impressive than trying to brush it aside.

• This result could be explained by [alternative mechanism] – how would you rule that out?
• Your n numbers are quite low for this type of experiment – how confident are you in these conclusions?
• How would your findings hold up if you used a different model organism or cell line?
• A colleague in your lab repeats this experiment and gets different results – what would you conclude?
• What is the weakest part of your thesis, and how would you strengthen it if you had another year?
• How do you account for potential off-target effects in your experimental system?
• If this finding doesn't replicate, what does that mean for the rest of your thesis?

Ready to practise? These are the kinds of questions your examiners will ask – but in a real viva, they won't stop at the first answer. They'll follow up, probe deeper, and test how well you can think on your feet. Try VivaCoach to practise with AI-powered follow-up questions tailored to your thesis.

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